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Stereo Upgrade: Subwoofer, Amp and Custom Amp-Cover It may look like a mini-mite but, with a new subwoofer, this Mini Cooper gets a mighty thump. From "Tricked Out" episode DTRK-212

(Continued from page 2)

Installing the Amp and Custom Cover

Andrew continues the radio conversion in the Mini Cooper by installing an amplifier in the rear of the car. The amplifier will be installed in the rear of the car, right next to the car's battery.

Safety Alert: As a standard safety precaution, always disconnect the vehicle's negative battery cable before you begin work on any electrical or mechanical components.

The installed subwoofer and power-amp.

The amp is mounted with a custom-made cover.

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• With the negative battery terminal already disconnected, remove the nut on the negative cable terminal and attach the amp ground lead (figure A).

• Then replace the nut and pull enough ground cable up through the carpet slit to reach the amp.

• Attach the power cable to the large nut on the positive battery terminal (figure B) and tighten it down.

  Figure A

  Figure B

  
  

  Figure C

• Wire tie a fuse holder to the battery bracket to provide short-circuit protection (figure C).

  Important: Battery connections should always be fused within 18 inches of the battery.

• Finally, pull lots of extra cable up through the slit to connect to the amp.
  

  	Figure D
  	Figure E

• Now it's time to create a custom amp cover that will cover the mess of wires but also provide ventilation (figure D).

• First, measure the area you're trying to cover so you'll know how big you need to cut out the panel (figure E).

• Once you determine the amount of area you'd like to cover with the false floor take the amp to a workbench to construct the cover.

• Make tic marks at intervals around the one-eighth-inch press board, and then use a straight edge to transfer the measurements for both sides.
  

  Figure F

• Clamp the board to a table and cut along the marks with a jig saw. The amp will stick out of the top of the box for ventilation, so measure the top of the amp at the cover height to determine how big that hole will need to be (figure F).
  

• Measure the length of the amp at the top of the supports (figure G) then add one-quarter-inch to leave space for the vinyl and ventilation.

• Next, find the center of the board and make a mark. Make tic marks from the center out for the inside cut and then connect the marks with a straight edge and prepare to cut out the inner square.

• Clamp the board to the table and drill a starter hole at each corner for the jig saw blade. Then cut the center portion out (figure H) and smooth any edges after the hole is cut.

  Figure G

  Figure H

  
  

  	Figure I
  	Figure J

• Once the hole is complete, test the cover on the amp to make sure it fits (figure I).

• The amp cover supports are constructed out of a 2x2 board that attaches to either end of the panel along the short side of the cover.

• In the Mini, the outside support needs to be cut shorter to allow clearance for a raised area of the floor.

• Cut these to length, and then glue them to the board (figure J).

• To further secure them, pre-drill holes with a counter-sink bit and add small screws to the supports on either side.
  
  
• You can use any material that matches your interior to cover the panel. For the project car, medium-gray vinyl was chosen. With the vinyl face down lay the top of the box down and trace around it leaving four inches of material to wrap around the edges.
  

• Once your material is cut (figure K) spray adhesive onto the top of the box and then position it onto the vinyl (figure L). Spray adhesive is pretty potent, so make sure to have adequate ventilation and wear safety goggles whenever you use it.

  Figure K

  Figure L

  
  

• Secure the material and then cut an "X" in the center with a craft knife.

• Fold the inside over and cut away the excess at each point of the triangle.

• At each corner, cut straight lines extending the edges of the board and remove the excess fabric.

• Cut an additional line at the edge that will wrap up and onto the foot, and then repeat the corner trimming around the rest of the panel.

• Spray adhesive onto the board (figure M) and fold the edges over to the inside (figure N).

  Figure M

  Figure N

  
  

• Continue spraying, folding and trimming until the amp cover is complete.

• Allow cover to dry for about 30 minutes before installing it over your amp.

• While you're waiting for the cover to dry, you can wire up your amp.

• Run speaker wires down through the hole in the carpet, leaving enough slack to run them along the rear seat to the side storage bin where the sub enclosure will mount (figure O).

• At the amp end, cut and strip the wires and connect them to the amp with the provided allen wrench.

• Pull the wires away from the cables and plug the RCA connection into the inputs on the side of the amp (figure P).

  Figure O

  Figure P

  
  

• Strip the wire, slide it into the terminal on the other side and tighten it down (figure Q).

• Attach both the positive and negative wire from the battery to the amp and tighten them securely.

• Pull the excess wires through the carpet to clean them up, then reconnect the negative terminal at the battery.

• Flip the carpet down, and set the new custom amp cover in place (figure R).

  Figure Q

  Figure R

  
  
  
  

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  RELATED PROJECTS: Acrylic Subwoofer Enclosure: Completion Acrylic Subwoofer Enclosure: Glue-Up and Amp-Wiring Acrylic Subwoofer Enclosure: Box Panels Acrylic Subwoofer Enclosure: Prep Work WEB-EXTRA: Online Volume Calculator for Speaker Enclosures

  
  

  ALSO IN THIS EPISODE:
  	Stereo Upgrade: Subwoofer, Amp and Custom Amp-Cover